iOS - Creating multi page PDF from HTML content

Question

I have a long html page and wanted to convert it in to a multipage PDF file.

I have followed the instructions provided in apple and here - how to make multi page PDF for a given string content.

But the formatting the NSString ( with some like data ) is difficult than creating a html page. I have created this html and displaying it in a UIWebView.

Now I want to create a PDF out of this HTML to a Multi page PDF file.

The code I'm using can create single PDF.

- (void)createPDFfromUIView:(UIWebView *)aView saveToDocumentsWithFileName:(NSString*)aFilename
{
    // Creates a mutable data object for updating with binary data, like a byte array
    NSMutableData *pdfData = [NSMutableData data];

    // Points the pdf converter to the mutable data object and to the UIView to be converted
    UIGraphicsBeginPDFContextToData(pdfData, aView.bounds, nil);
    UIGraphicsBeginPDFPage();
    CGContextRef pdfContext = UIGraphicsGetCurrentContext();


    // draws rect to the view and thus this is captured by UIGraphicsBeginPDFContextToData

    [aView.layer renderInContext:pdfContext];

    // remove PDF rendering context
    UIGraphicsEndPDFContext();

    // Retrieves the document directories from the iOS device
    NSArray* documentDirectories = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask,YES);

    NSString* documentDirectory = [documentDirectories objectAtIndex:0];
    NSString* documentDirectoryFilename = [documentDirectory stringByAppendingPathComponent:aFilename];

    // instructs the mutable data object to write its context to a file on disk
    [pdfData writeToFile:documentDirectoryFilename atomically:YES];
    NSLog(@"documentDirectoryFileName: %@",documentDirectoryFilename);
}

Can any one give some help ?

Answer 1

I created a class based on every good advice I found around. I've been digging a lot and I hope my class will offer some good start for anyone trying to create multi-page PDF directly out of some HTML source.

You'll find the whole code here with some basic sample code : https://github.com/iclems/iOS-htmltopdf

I had just the same issue as you and my requirements were: - full PDF (real text, no bitmap) - smart multi-pages (compared to cutting a full height webview every X pixels...)

Thus, the solution I use is pretty nice as it resorts to the same tools iOS uses to split pages for print.

Let me explain, I setup a UIPrintPageRenderer based on the web view print formatter (first tip) :

UIPrintPageRenderer *render = [[UIPrintPageRenderer alloc] init];

[render addPrintFormatter:webView.viewPrintFormatter startingAtPageAtIndex:0];

CGRect printableRect = CGRectMake(self.pageMargins.left,
                              self.pageMargins.top,
                              self.pageSize.width - self.pageMargins.left - self.pageMargins.right,
                              self.pageSize.height - self.pageMargins.top - self.pageMargins.bottom);

CGRect paperRect = CGRectMake(0, 0, self.pageSize.width, self.pageSize.height);

[render setValue:[NSValue valueWithCGRect:paperRect] forKey:@"paperRect"];
[render setValue:[NSValue valueWithCGRect:printableRect] forKey:@"printableRect"];

NSData *pdfData = [render printToPDF];

[pdfData writeToFile: self.PDFpath  atomically: YES];

In the meantime, I have created a category on UIPrintPageRenderer to support:

-(NSData*) printToPDF
{
    [self doNotRasterizeSubviews:self.view];

    NSMutableData *pdfData = [NSMutableData data];

    UIGraphicsBeginPDFContextToData( pdfData, CGRectZero, nil );

    [self prepareForDrawingPages: NSMakeRange(0, self.numberOfPages)];

    CGRect bounds = UIGraphicsGetPDFContextBounds();

    for ( int i = 0 ; i < self.numberOfPages ; i++ )
    {
        UIGraphicsBeginPDFPage();

        [self drawPageAtIndex: i inRect: bounds];
    }

    UIGraphicsEndPDFContext();

    return pdfData;
}